James Middleton shares throwback photo, praises 'wonderful sister' Kate

James Middleton and his older sister, the Duchess of Cambridge (PA)

James Middleton has praised his “wonderful sister” Kate as her survey on Early Years care draws to a close.

The Boomf founder, 32, shared a snap of him as a child with his grandparents’ dog and shared the link to his sister’s survey in his bio.

In the post, he said: “This isn’t a post about dogs...brace yourselves....BUT it’s in huge support of my wonderful Sister’s ‘Early Years’ initiative to ask “5 big questions on the under fives”.

“If you have 5 minutes & live in the UK join the biggest conversation on early childhood. Like me even if you don’t have children, your own experiences will help invest in the future of the next generation.”

The Duchess of Cambridge is running a survey in conjunction with Ipsos MORI which aims to spark a nationwide conversation on early years care and development.

James with his sister Pippa at Wimbledon 2019 (Getty)

Read more: Giovanna Fletcher admits she didn't sleep the night before interviewing the Duchess of Cambridge

It’s become a passion of hers since she married Prince William in 2011 and worked on it for about eight years before launching the survey.

To promote it, Kate travelled to all four nations of the UK, most recently in a surprise visit to Belfast in Northern Ireland and Aberdeen in Scotland.

In Belfast she toured a farm and handled a snake, while in Aberdeen she visited Social Bite cafe and spoke to those whose early years played a role in later life.

The duchess has toured the UK with her survey 5 Big Questions on the Under-Fives (Getty)

Read more: Duchess of Cambridge admits she feels 'mum guilt' and says she practiced hypno-birthing in labour

Fans of Middleton praised him for supporting his big sister, with one writing: “Catherine is really lucky to have such a supportive family.”

Another added: “How nice and important it is family support. I admire very much yours and HRH causes.”

James Middleton pictured with his dogs (Getty)

Middleton runs customisable marshmallow company Boomf and is an ambassador for Pets as Therapy. He has several dogs himself, and most of his social media posts focus on his animals.

Read more: Duchess of Cambridge gives 5 Big Questions survey final push in rare video

In October he gave an interview in which he revealed his battle with depression, and how he took steps to recovery.

James Middleton is engaged to Alizee Thevenet (Getty)

He is engaged to Alizee Thevenet a City worker he reportedly met at the South Kensington Club when she said hello to his dog Ella.

The survey closes on Friday, 21 February and the Royal Foundation may release the results in spring.